• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1278-1284
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• 2008

This study carried out bender element tests in a calibration chamber in order to estimate the characteristics of soil specimen prepared in a calibration chamber. Basically, the purpose of bender element test is to measure the shear wave velocity. Bender element test cannot only confirm the status of soil specimen deposited in a chamber, but also estimate the consolidation process indirectly. In order to carry out bender element test in a calibration chamber, a pair of bender elements was installed inside the chamber, using the 'ㄷ' shaped frame. For the sandy soils having various relative densities in various stress conditions, the maximum shear modulus was estimated. From the comparison with bender element test results in a triaxial testing device, testing device and procedure was validated.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.99-102
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• 2007

Pressure Sensitive Paint(PSP) means a reacting paint in pressure. The calibration of PSP and the wind tunnel test of PSP painted model are required to measure pressure using by PSP. Therefore, the post processing from these results shows the information and image of the pressure distribution. PSP can show the information of total pressure from the wind tunnel test and the calibration. In this study, equipments of PSP are composed, and calibration is accomplished using by PSP. Results of design and manufacturing calibration chamber till ability of advance calibration system study.

• Geomechanics and Engineering
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• v.2 no.3
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• pp.177-190
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• 2010

This paper presents the details of indigenous development of the piezovibrocone and calibration chamber. The developed cone has a cylindrical friction sleeve of $150cm^2$ surface area, capped with a $60^{\circ}$ apex angle conical tip of $15cm^2$ cross sectional area. It has a hydraulic shaker, coupled to the cone penetrometer with a linear displacement unit. The hydraulic shaker can produce cyclic load in different types of wave forms (sine, Hover sine, triangular, rectangular and external wave) at a range of frequency 1-10 Hz with maximum amplitude of 10 cm. The piezovibrocone can be driven at the standard rate of 2 cm/sec using a loading unit of 10 ton capacity. The calibration chamber is of size $2m{\times}2m{\times}2m$. The sides of the chamber and the top as well as the bottom portions are rigid. It has a provision to apply confining pressure (to a maximum value of $4kg/cm^2$) through the flexible rubber membrane inlined with the side walls of the calibration chamber. The preliminary static as well as dynamic cone penetration tests have been done sand in the calibration chamber. From the experimental results, an attempt has been made to classify the soil based on friction ratio ($f_R$) and the cone tip resistance ($q_c$).

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1359-1364
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• 2008

It is well known that the standard penetration test (SPT) has been used in all over the world to get geotechnical properties of the ground. However, it is difficult to apply the SPT to the dense sand, gravel, weathered rock, etc. For the application of the SPT in these grounds, it is necessary to change in the diameter and the impact energy of the SPT. For the improvement of site investigation technology, Large Penetration Testing device (KICT-type LPT) was developed and applied to the in situ condition. The drop height and weight of the hammer in developed system were decided as 760mm and 150kg, respectively. And the developed sampler has the inner diameter of 63 mm and the length of 500 mm with the adjustment of energy ratio to the SPT of 1.5. In this study, the performance of KICT-type LPT was evaluated by using a calibration chamber system and pile driving analyzer (PDA)

• Proceedings of the Korean Geotechical Society Conference
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• 2000.02a
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• pp.42-58
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• 2000

본 연구의 목적은 연약지반의 압밀계수 측정에 있어 Piezocone 관입시험을 이용할 때 관입시험자체의 정확성과 시험결과들에 미치는 여러 가지 지반공학적 영향요소들을 고려하려는데 있다. 본 연구의 연구실험방법으로는, Piezocone 관입을 위한 연약모형지반 조성을 위하여 초대형 Slurry Consolidometer에 Free Stress 상태의 Slurry를 45일간 압밀시킨 후 Automatic Computer Control Calibration Chamber (LSU/CALCHAS; Louisiana State University Calibration Chamber System)에 옮긴후 다시한번 압밀시키는 Two-Stage Consolidation Method를 사용하였다 동시에 연약모형지반내에 8개의 Piezometer를 설치하여 Piezocone 관입시 유발되는 지반 내에서의 과잉간극수압의 변환을 측정하였다. 총 25개의 Piezocone 시험중 4개는 Standard 10$\textrm{cm}^2$ Piezocone이고, 나머지 21개는 Miniature Piezocone이 사용되었다. 모형지반은 여러 가지 Boundary Condition들과 Stress Condition 그리고 Stress History등을 고려하여 조성되었다. 또한 Dissipation Test직후의 압밀특성을 확인하기 위하여 0.01초당 한 개이상의 실측점을 측정할 수 있는 Digital-Oscilloscope를 이용하였다. 특히 Dissipation Test, 즉시 Piezocone의 Filter Element에 잡히지 않는 과잉간극수압의 Initial Drop 존재에 관한 기존의 추측을 실제 실험치로 확인할 수 있었다.

• Journal of the Korean Geotechnical Society
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• v.16 no.3
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• pp.99-106
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• 2000

피에조콘 관입 및 소산 시험이 Calibration Chamber 및 미니 피에조콘을 이용하여 수행되었다. 시험은 정규압밀 및 과압밀 점토에 대하여 정지토압 상태에서 실시되었으며 UI (filter element at cone tip), U2 (filter element above cone base) 두 종류의 피에조콘이 사용되었고 0.3cm/sec, 0.6cm/sec의 관입속도가 적용되었다. 오실로스코프를 사용하여 소산시험 초기 간극수압의 급격한 변화를 측정하였다. 시험결과로부터 관입속도, filter element 위치, 과압밀비가 피에조콘 관입 및 소산시험의 결과에 미치는 영향을 고찰하였으며 입도분포시험을 실시하여 관입시험 전후의 입도분포 치이를 고찰하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1188-1191
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• 2017

Thrust is one of the crucial performance parameter of a combustion chamber in the combustion chamber development test. So it is very important to measure an accurate thrust. Thrust calibration test was performed to identify the system characteristics, resistance and linearity of a vertical thrust measurement system(TMS) for accurate thrust measurement. It has been found 6.9% ~ 8.6% errors between the measured thrust by TMS calibration equations and theoretical thrust. It has been confirmed that the TMS calibration is necessary to be performed with the propellant lines connected to the combustion chamber for accurate thrust measurement.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.397-404
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• 2002

The bearing capacity of open-ended piles is affected by the degree of soil plugging, which is quantified by the IFR. There is not at present a design criterion for open-ended piles that explicitly considers the effect of IFR on pile load capacity In order to investigate this effect, model pile load tests using a calibration chamber were conducted on instrumented open-ended piles. The results of these tests show that the IFR increases with increasing relative density and increasing horizontal stress of soils. The unit base and shaft resistances decrease with increasing IFR. Based on the results of the model pile tests, new empirical relations for base load capacity and shaft load capacity of open-ended piles are proposed. In order to check the accuracy of predictions made with the proposed equations, the equations were applied to the full-scale pile load test preformed in this study, Based on the comparisons with the pile load test results, the proposed equations appear to produce satisfactory predictions.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.1
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• pp.6-12
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• 2008

ISO pneumatic cylinder reliability test requires air leakage measurement. Air cylinder has many parts and the leakage shall be measured before, during and after endurance test, and, the leakage should smaller than the specified value. The existing measurement method needs complex operation and the calibration of leak detector, and, has to separate the testing cylinder from endurance test device, which causes the change of contact condition of seal in the cylinder. Therefore, it is hard to evaluate the air leakage during endurance test, and guarantee the reliability of the conventional measurement method. In this paper, a new method for air leakage measurement using isothermal chamber, which does not requires calibration or temperature compensation, and, can measure air leakage accurately with quite simple operations, is proposed. As a result, reliability of air leakage measurement can be improved because the proposed method does not have to separate the testing cylinder from the endurance test device for air leakage measurement. The effectiveness of the proposed method is proved by error analysis of leak measurement from experimental result.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.490-495
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• 2009

In this study, estimate solution of ultimate axial capacity for axial loaded pile is proposed using step-wised shape. This is verified for effective appling on realistic factor by calibration chamber tests. Estimation method of ultimate axial capacity in this study is verified by calibration chamber test. The results of ultimate axial capacity through this proposed method have sufficiently low standard derivations and COVs. Also, this is verified through test that method is similarly resulted with measured values.